Annotation of OpenXM_contrib/gnuplot/ctrl87.h, Revision 1.1.1.1
1.1 maekawa 1: /* $Id: ctrl87.h,v 1.2 1998/03/22 22:31:27 drd Exp $ */
2:
3: /* GNUPLOT - ctrl87.h */
4:
5: /*[
6: * Copyright 1986 - 1993, 1998 Thomas Williams, Colin Kelley
7: *
8: * Permission to use, copy, and distribute this software and its
9: * documentation for any purpose with or without fee is hereby granted,
10: * provided that the above copyright notice appear in all copies and
11: * that both that copyright notice and this permission notice appear
12: * in supporting documentation.
13: *
14: * Permission to modify the software is granted, but not the right to
15: * distribute the complete modified source code. Modifications are to
16: * be distributed as patches to the released version. Permission to
17: * distribute binaries produced by compiling modified sources is granted,
18: * provided you
19: * 1. distribute the corresponding source modifications from the
20: * released version in the form of a patch file along with the binaries,
21: * 2. add special version identification to distinguish your version
22: * in addition to the base release version number,
23: * 3. provide your name and address as the primary contact for the
24: * support of your modified version, and
25: * 4. retain our contact information in regard to use of the base
26: * software.
27: * Permission to distribute the released version of the source code along
28: * with corresponding source modifications in the form of a patch file is
29: * granted with same provisions 2 through 4 for binary distributions.
30: *
31: * This software is provided "as is" without express or implied warranty
32: * to the extent permitted by applicable law.
33: ]*/
34:
35:
36: #ifndef __CONTROL87_H__
37:
38:
39: #define __CONTROL87_H__
40:
41:
42: #ifdef __CONTROL87_C__
43: #define EXTERN
44: #else
45: #define EXTERN extern
46: #endif
47:
48:
49: /* 8087/80287 Status Word format */
50:
51: #define SW_INVALID 0x0001 /* Invalid operation */
52: #define SW_DENORMAL 0x0002 /* Denormalized operand */
53: #define SW_ZERODIVIDE 0x0004 /* Zero divide */
54: #define SW_OVERFLOW 0x0008 /* Overflow */
55: #define SW_UNDERFLOW 0x0010 /* Underflow */
56: #define SW_INEXACT 0x0020 /* Precision (Inexact result) */
57:
58: /* 8087/80287 Control Word format */
59:
60: #define MCW_EM 0x003f /* interrupt Exception Masks*/
61: #define EM_INVALID 0x0001 /* invalid */
62: #define EM_DENORMAL 0x0002 /* denormal */
63: #define EM_ZERODIVIDE 0x0004 /* zero divide */
64: #define EM_OVERFLOW 0x0008 /* overflow */
65: #define EM_UNDERFLOW 0x0010 /* underflow */
66: #define EM_INEXACT 0x0020 /* inexact (precision) */
67:
68: #define MCW_IC 0x1000 /* Infinity Control */
69: #define IC_AFFINE 0x1000 /* affine */
70: #define IC_PROJECTIVE 0x0000 /* projective */
71:
72: #define MCW_RC 0x0c00 /* Rounding Control */
73: #define RC_CHOP 0x0c00 /* chop */
74: #define RC_UP 0x0800 /* up */
75: #define RC_DOWN 0x0400 /* down */
76: #define RC_NEAR 0x0000 /* near */
77:
78: #define MCW_PC 0x0300 /* Precision Control */
79: #define PC_24 0x0000 /* 24 bits */
80: #define PC_53 0x0200 /* 53 bits */
81: #define PC_64 0x0300 /* 64 bits */
82:
83: /**************************************************************************/
84: /************************* Type declarations **************************/
85: /**************************************************************************/
86:
87: /**************************************************************************/
88: /************************ Function declarations ***********************/
89: /**************************************************************************/
90:
91: /*
92: _control87 changes floating-point control word.
93:
94: Declaration:
95: ------------
96: unsigned short _control87(unsigned short newcw, unsigned short mask);
97:
98: Remarks:
99: --------
100: _control87 retrieves or changes the floating-point control word.
101:
102: The floating-point control word is an unsigned short that specifies the
103: following modes in the 80x87 FPU:
104: o allowed exceptions
105: o infinity mode
106: o rounding mode
107: o precision mode
108:
109: Changing these modes allows you to mask or unmask floating-point exceptions.
110:
111: _control87 matches the bits in mask to the bits in newcw.
112:
113: If any mask bit = 1, the corresponding bit in newcw contains the new value
114: for the same bit in the floating-point control word.
115:
116: If mask = 0000, _control87 returns the floating-point control word without
117: altering it.
118:
119: Examples:
120: ---------
121: Switching to projective infinity mode:
122: _control87(IC_PROJECTIVE, MCW_IC);
123:
124: Disabling all exceptions:
125: _control87(MCW_EM, MCW_EM);
126:
127: Return Value:
128: -------------
129: The bits in the value returned reflect the new floating-point control word.
130: */
131: EXTERN unsigned short _control87(unsigned short newcw, unsigned short mask);
132:
133:
134: /**************************************************************************/
135: /************************** Global variables **************************/
136: /**************************************************************************/
137:
138:
139:
140: #ifdef __CONTROL87_C__
141: #else
142: #endif
143:
144:
145: #undef EXTERN
146:
147:
148: #endif
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